Lac Mathias is a Lake located in Hébertville; Lac-Saint-Jean-Est, Quebec.

• Latitude: 48° 18' 11'' North   (decimal: 48.3030556)
• Longitude: 71° 40' 39'' West   (decimal: -71.6775)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Location: Hébertville; Lac-Saint-Jean-Est
• Atlas of Canada Locator Map: Lac Mathias
• GPS Coordinate Locator Map: Lac Mathias Lat/Long